//------------------------------------------------------------------------------
// <copyright company="Telligent Systems">
//     Copyright (c) Telligent Systems Corporation.  All rights reserved.
// </copyright> 
//------------------------------------------------------------------------------

using System;


namespace CommunityServer.Components
{
	/// <summary>
	/// Provides logic to move to and from User and Server time
	/// </summary>
	public class UserTime
	{
		private UserTime(){}

        /// <summary>
        /// Converts a date to the Client/user's local time
        /// </summary>
		public static DateTime ConvertToUserTime(DateTime dt, double ClientTimeZone)
		{
			return dt.AddHours(FromClientToServerFactor(ClientTimeZone, CSContext.Current.SiteSettings.TimezoneOffset));
		}

		public static DateTime ConvertToUserTime(DateTime dt)
		{
			CSContext csContext  = CSContext.Current;
			return dt.AddHours(FromClientToServerFactor(csContext.User.Profile.Timezone, csContext.SiteSettings.TimezoneOffset));
		}


        /// <summary>
        /// Converts a date to the Servers local datetime
        /// </summary>
		public static DateTime ConvertToServerTime(DateTime dt, double ClientTimeZone)
		{
			return dt.AddHours(FromServerToClientFactor(ClientTimeZone,CSContext.Current.SiteSettings.TimezoneOffset));
		}

		public static DateTime ConvertToServerTime(DateTime dt)
		{
			CSContext csContext  = CSContext.Current;
			return  dt.AddHours(FromServerToClientFactor(csContext.User.Profile.Timezone,csContext.SiteSettings.TimezoneOffset));
		}

        /// <summary>
        /// Returns the local time of the current user
        /// </summary>
		public static DateTime CurrentUserTime
		{
			get
			{
                if(CSContext.Current.User.IsAnonymous)
                    return DateTime.Now;

				return DateTime.Now.AddHours(ClientToServerTimeZoneFactor);
			}
		}

		/// <summary>
		/// Returns the local server time
		/// </summary>
		public static DateTime CurrentServerTime
		{
			get {return DateTime.Now;}
		}

		#region helpers

		/// <summary>
		/// Returns the TimeZone factor for the current user
		/// </summary>
		private static double ClientToServerTimeZoneFactor
		{
			get
			{
				CSContext context = CSContext.Current;
				return FromClientToServerFactor(context.User.Profile.Timezone,context.SiteSettings.TimezoneOffset);
			}
		}

		private static double FromClientToServerFactor(double Client, double Server)
		{
			return Client - Server;
		}

		private static double FromServerToClientFactor(double Client, double Server)
		{
			return Server - Client;
		}

        /// <summary>
        /// Returns the TimeZone factor the server compared to the current user
        /// </summary>
		private static double ServerToClientTimeZoneFactor
		{
			get
			{
				CSContext context = CSContext.Current;
				return FromServerToClientFactor(context.User.Profile.Timezone,context.SiteSettings.TimezoneOffset);
			}
		}
		#endregion
	}
}
